Traditional anti-theft devices such as alarms, while a reasonable front-line deterrent to thefts, cannot actually stop robberies once the perpetrator has broken in. This is because an estimated 85 percent of robberies are completed before security or police have even arrived on-site. An effective alternative to traditional anti-theft devices is a 'Smoke Cloak' system which releases a harmless vapour reducing visibility to practically zero and stopping would-be burglars.